L-Theanine and L-Tyrosine

L-Theanine and L-Tyrosine

Characteristics and properties of L-Theanine

L-theanine is not so famous but very common amino acid, available mostly in green tea. It is one of the few nutritional supplements, which passes the blood-brain barrier, as a result, it has a direct effect on the central nervous system and directly affects brain activity. L-theanine has a positive effect on calming the body in several ways. It increases levels of dopamine – a neurotransmitter that balances the states of depression and lack of concentration, not addictive.

This amino acid penetrates the blood-brain barrier and is distributed in the intercellular spaces of the brain cells – neurons and astrocytes, which makes it an effective anti-stress agent. It has a beneficial effect on the blood circulation of the brain, the immune system and act as an antioxidant, keeping the life of the nerve cells.

L-theanine enhances immune responses against infections, provides a rapid immune response by increasing the ability of T cells to cope with the disease. It has a significant effect on the release or reduction of neurotransmitters (serotonin and dopamine), improving the memory capacity.

Why should we take L-Theanine?

L-theanine is an effective anti-stress agent. Acts 30-40 minutes after dosing. Stress and anxiety are conditions which disrupt the hormonal balance and lead to overall poor health. This is a medical condition in which part of the symptoms are of the mental and emotional sphere: anxiety, restlessness, poor sleep, obsessive fears, concentration disorders, depression, aggression. Hence, the stress suppresses the immune system, making the body vulnerable to infections.

When can you use L-Theanine?

  • Chronic Fatigue Syndrome
  • Mental and physical stress
  • Anxiety, insomnia
  • Depression
  • Impaired memory and concentration
  • Decreased immunity
  • Premenstrual syndrome

L-Theanine Side effects

There are no known side effects. Not suitable for use as the sole source of nutrition. The product should be part of a balanced diet and a healthy lifestyle, but also under medical supervision. Do not be taken by pregnant women, nursing mothers and children under 7 years of age.

Where can we find L-Theanine?

Theanine is one of many active ingredients in green tea which undoubtedly can have the name – a magic gift from nature. Theanine brings some of the most desirable properties of green tea, such as brings calmness, good mood, and heart health. Although it is not a popular amino acid, the scientific basis behind L-theanine is stable enough to convince us to give a chance to this so valuable supplement. If you select L-theanine, do not expect it to replace the green tea and use it according to its unique properties.

What is L-Tyrosine and what is its role?

L-Tyrosine is one of the twenty amino acids which are building essential proteins for the body. Under normal conditions, the body can not synthesize this amino acid from phenylalanine.

The main role of L-tyrosine in the metabolism is as part of the synthesis of neurotransmitters and hormones, which play the role of important substances in the body. Thus, from L-tyrosine in the central, peripheral nervous system and adrenal glands are synthesized dopamine and adrenaline. Additionally, the skin pigment melanin also is synthesized from L-tyrosine.

Potential positive effects of L-Tyrosine

  • Improves recovery after sport
  • Improves resistance
  • Reduces mental fatigue and stress
  • Protects muscles from catabolic processes
  • Enhances fat burning
  • Increases the number of red and white blood cells
  • Raises mood

L-Tyrosine most feature its impact on mental activity and stress. Tyrosine also has direct application in athletes to strict sports regime, which is subject to the risk of over-training.

Furthermore, several studies made by the US Army has shown that animals supplemented with L-Tyrosine have better low-temperature stability throughout by others who were not taking L-Tyrosine. Also, quite studies suggest that L-Tyrosine fights negative effects from prolonged sleep deprivation.

Content of L-Tyrosine in the diet

L-tyrosine is an ingredient in most foods of plant and animal origin in the greatest concentrations because it is present in meat, dairy products, sea products and legumes.

Possible side effects of taking L-Tyrosine

In general, adults can safely take L-tyrosine without fear of side effects, but at the optimum dosage of the product. Although side effects are relatively rare in overdose tyrosine can cause:

  • Headache
  • Nausea
  • Heartburn
  • Joint pain
  • Fatigue

Contraindications for L-Tyrosine intake

Therefore, that L-tyrosine has a role in the production of the hormone thyroxine, it is not recommended as a supplement by people suffering from diseases of the thyroid gland before consulting a doctor.

Also, people taking other medications (such as drugs for Parkinson’s disease) should not take supplements based on tyrosine, due to the risk of reduced performance and interactions. Finally, L-tyrosine as a supplement should not be taken by pregnant women, nursing mothers, and children.

Why is it necessary taking L-Tyrosine?

When the body is under stress or fatigue and with an increase in age, the concentration of tyrosine in the body significantly decreases. A deficiency of this amino acid can cause low blood pressure and low body temperature, and more prolonged deficiency can cause hypothyroidism – enlargement of the thyroid gland.

L-Theanine and L-Tyrosine are popular as a dietary supplement to reduce the effects of stress. Furthermore, the amino acid often accompanies diets for weight reduction, as a means to suppress appetite.


About Jane Peterson

Jane Peterson is a supportive nutrition and fitness coach and registered dietitian nutritionist known for her health advices and innovative ideas to inspire and motivate people to reach their goals. She has a passion for personal training and enjoys motivating people, using specific exercise programs and track their progression for success. As a parent herself, Jane Peterson knows what it means to have to work hard to keep a good shape during pregnancy and after having a baby. She is interested about improving the way children eat, pediatric nutrition and family meal planning. Jane has several years of personal and professional experience and is practicing as a freelance food and health writer. She works personally with a small number of hand picked clients, transforming their health and their physiques using her four key elements of wellness: lifestyle, exercise, nutrition and supplementation.